Combined cofferdam and pier fender construction method



June 9, 1936. J. B. STRAUSS 2,043,452

COMBINED COFFERDAM AND PIER FENDER CONSTRUCTION METHOD Filed July 18, 1954 5 Sheets-Sheet l INVENTOR Joseph B. Sfrauss ATTORN EY June 9, 1936. J B STRAUSS 2,043,452

COMBINED COFFERDAM AND PIER FENDER CONSTRUCTION METHOD Filed July 18, 1954 3 Shets-Sheet INVENTOR Jase h B. Sfrauss Y BY -AQ\W/ ATTORNEY June 9, 1936. J B TRA 2,043,452

COMBINED COFFERDAM AND PIER FENDER CONSTRUCTION METHOD Filed July 18, 1954 3 SheetsSheet 5 Fig. II

IINVENTOR Joseph B. Sfraws ATTORNEY Patented June 9, 1936 PATENT OFFICE COMBINED COFFERDAM AND PIER FENDER CONSTRUCTION METHOD Joseph B. Strauss, San Francisco, Calif.

Application July 18, 1934, Serial No. 735,853

2 Claims.

This invention relates to improvements in combined' cofierdam andpier fender construction.

' The principal object of this invention is to construct a cofferdamfor a bridge pier which will thereafter become a permanent pier fender spaced from the pier proper and capable of withstanding any heavy shock which might injure the pier and consequently the safety of the bridge supported thereon.

A further object is to construct such a device in such a manner that hazardous underwater conditions may be coped with.

An additional object is to construct a device of this character wherein the action of the waves may be overcome.

A still further object is to construct a device which will require a minimum amount of equipment and one which will conform to all approved engineering practices.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Fig. I is a top plan view of a bridge pier having my combined cofferdam and bridge fender positioned thereabout,

Fig. II is a cross sectional view taken on the line 2-2 of Fig. I,

Fig. III is a top plan view of Fig. IV showing the cofferdam partly completed and the manner in which a floating caisson is moved into the protecting walls of the cofferdam,

Fig. IV is a side elevation of Fig. III and showing the coiferdam in cross section,

Fig. V is a cross sectional view of the completed cofierdam and showing the caisson sunk and resting upon the shoulder of the cofferdam, and

Fig. VI is a perspective view illustrating the various steps incident to the formation of my invention.

In bridge construction it has been common to build a bridge pier by first erecting a caisson which is sunk in any approved manner so that a proper footing may be excavated for the bridge pier. After the bridge pier is completed it is common to construct a fender about the bottom of the pier so that any ships or other matter floating in the water will not contact the pier and cause damage thereto. It is a comparatively simple matter to build such a structure as above described where the water is shallow or free from currents. It is exceedingly difficult to build such a structure where there is deep water or where the Water isturbulent and particularly so where there is wave action. Applicant has, therefore,

deviseda system for building such a structure v under the most adverse conditions.

Referring to the drawings, it will be noted that applicant first excavates a comparatively shallow footing below the normal surface, which footing is shown at 5, and adjacent one edge thereof, that is assuming that the footing has considerable area, a form 6 is placed. Within this form concrete is poured, a similar form is placed adjacent and in this manner an outline of concrete blocks is formed entirely around the margin of the excavated footing. These blocks are indicated by the numeral 7. After the first row of blocks has been formed, a form 8 is lowered so as to rest upon one of the blocks 7 and this form is then filled with concrete. Similar forms are so placed that a complete circle of unit structures 9 are cast upon the bottom row of blocks 1. A third row of blocks I l are, likewise, cast upon the blocks 9. Depending upon the depth of the water, such a structure will commence to form a serious impedance to the flow of the water and consequently I do not propose to carry my structure high enough to set up extreme eddy currents, and therefore I propose to erect upon the blocks ll an open work metal structure 12 which in turn supports a roadway l3. As soon as the metal frame is entirely erected and properly braced I attach form boards to small portions of the framework and fill these portions with concrete, the result being that the entire bracing of the metal super-structure, together with the Weight of the roadway and. equipment positioned thereon, will be more than sufficient to withstand the most severe wave action or currents that might be encountered and by thus forming section after section I may complete the entire cofferdam in a most expeditious manner.

Where it is necessary to employ a caisson, particularly of the floating type, I-purposely omit some of the blocks or units at one end of the cofferdam, as illustrated in Figs. III and IV. (It might be here mentioned that in the casting of these units underwater, the various units unite and are bound together so that the entire structure is a monolithic mass and the outline of the blocks shown in Fig. VI are merely lines to designate the manner in which the structure is built up. Therefore, the letter B represents the fender as a whole.) If this type of floating caisson A is employed, the same is floated into position, after which the interior is filled with concrete so that the caisson sinks until its cutting edge [4 rests upon the shoulder I6 of the bottom of the cofferdam. A seal I! is then poured between the inner surface of the cofferdam and the outer surface of the caisson. The interior of the caisson A is of course filled with concrete as shown at l8, but before so doing it is preferable to cut away the shoulder l6 and fill the space with a plastic material l9. This arrangement prevents any transmission of downward stresses from the bridge pier to the cofferdam or fender.

From the foregoing it will be apparent that. I have devised a structure which will accomplish all of the objects above set forth and will produce; first a cofierdam and secondly abridge fender, and a structure which may be built under the most adverse conditions.

It is to be understood that the form ofmy invention herewith shown and described is to be taken as a preferred example of the same and that various changes relative to the material, size, shape and arrangement of parts may be resorted towithout departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim: 1. A method of forming a pier or cofferdam comprising excavating a footing, casting units in said footing in a substantially circular formation, said units being a fractional part of the completed structure, casting units superimposed upon said first units, mounting an open-work superstructure on said last mentioned units, and later embedding said superstructure in additional units of cast material.

2. The method of forming a combined fender and cofferdam for a subaqueous structure, which includes the excavation of a footing below water level, the casting of units in a circular formation in said footing, said units progressing in opposite directions from the: starting point of the circle to themeeting pointcat the opposite side of the circle, progressively casting additional units superimposed on said first mentioned units, all of said units being a fractional part of the height of the structure, mounting an openwork structure on said last mentioned units, later embedding said openwork structure in additional units of cast material, said embedding progressing verticallyin circular stages, whereby current actionthrough said structure is gradually stopped.

JOSEPH B. STRAUSS. 

